Automatic gear shift



Ma a-1, 1929. CI'VSPAHN J I 1,114.194

'AUTOMATLC EA SHIFT I Filed Oct. 29, 1928 s Sheets-Sheet 2 nasbafii l fMay 21, 1929. F, c, SPAHN 1,714,194

1 AUTOMATIC GEAR-SHIFT Filed Oct. 29, 1928 .5 Sheets-Sheet 3 F.C.Spdh'nPatented May 21, 1929.,

UNITED STATES,

v FRED o. sim an,- or sontnswro, Iowa.

AUTOMATIC GEAR SHIFT.

Application filed October 29, 192's. Serial No; 315,865."

The present invention relates to automatic means for shifting the changespeed gearing ,in an automobile power transmission mechanism.

An ob ect of the present inventlon 1s to provide automatic means of thischaracter \vhichjis under the control of the clutch pedal,

and wherein is eliminated the hand lever at present employed forshifting the gearing.

Another object of the invention is to provide a mechanism wherein thegearing mech anism will at all times be shifted into a neutral positionbefore a subsequent adjustment of the gearing may be made, the operationbeing automatieand not dependent upon the skill or memory of theoperator.

A still further object of the invention is to provide a device of thischaracter which is relatively simple in construction, comprises butrelatively few parts, which may be economically manufactured, and whichmay be readily installed or applied to the standard change-speed gearingmechanism at present used. i The invention also aims to provide certainimprovements which relate to the construction shown in applicants priorPatent Number 1,67 2,698. g

It is a primary object ofthis invention to eliminate confusion causedduring shifting of the gears of a selective gear transmission mechanismof an automobile, and to provide an indicator and a selector which willbe visible to the operator at all times for selecting and setting themechanism so as to change the speed as desired onlyupon the operation ofthe clutch pedal.

' The above, and various other objects and advantages of this inventionwill be brought out in and understood from the following detaileddescription of the present preferred embodiment, the same beingillustrated in the accompanying drawings, wherein: I Figure: 1 is alongitudinal section taken through the casing of a change speed gearingmechanism and adjacent parts, and showing the automatic gear shiftingmechanism of this invention applied thereto.

Figure- 2 is a detail plan view of the combined selector and indicatorused.

Figure 3 is a side elevation of the change speed gear mechanism showingthe improvements applied thereto, the parts being adj usted in highspeed position.

Figure 4 is a similar view, showing. the parts adjusted for reversedposition- Figure 5 is a top plan view of the transmission mechanismhaving the automatic devices of this invention applied thereto.-

Figure 6 is a side elevation, enlarged, of the actuating sector which isoperated through the clutch pedal.

Figure 7 is a detail side elevation of the selector cam employed. 1

Figure 8 is an end elevation of the same. Figure 9 is a transversesection through the selector cam taken on the line 99 of Figure arrow.

Figure 10 is a detail side elevation of the combined gear shifting dogand the neutral setting dog, an

Figure 11 is a face view of the same. Referring now to the drawings fora more 7 and looking in the direction of the particular description ofthe invention, and

wherein like numerals of reference designate corresponding partsthroughout the several views, designates the drive shaft or crank shaftof an engine upon which is mounted a. fly wheel 21 having the usualstarter reinforcements, and which cooperates with a movable clutchmember 23 for coupling the drive shaft 24 which extends through thetransmission casing 25. The fly wheel 21 and adjacent'parts are shown asmounted in a clutch housing 26, which may be a part of the transmissioncasing 25, but which is preferabl separated therefrom by a partition 27whic provides a support for bearings for the various shafts.

- The shiftable clutch element '23 is provided with the usual collar 28,with which engages a fork 29 mounted on a transfer shaft 30 to which theclutch pedal 31 is secured. The

clutch pedal 31, shaft 30 and fork 29 are of the usual type, and aredisposed in the usual position for operation by the foot of the operatorwhen releasing the clutch. The change speed gear mechanism may be of theusual type as shown, and wherein the drive shaft 24 is provided with asmall gear 32, an intermediate gear 33, and a large gear 34. The gears33 and 34 are keyed for longitudinal and independent sliding movementupon the rear section 35 of .thedrivje shaft, and each gear33 and 34, isprovided with a peripherally "grooved collar 36 by means of which thegears may be independently shifted.

The transmission casing 25 is also provided witha-counter shaft 37 whichis disposed in parallel relation with respect to the drive fixed thereonnear its forward end a large shaft 24 and its section 35, and which has.J

gear wheel 38, which meshes at all times with 41 and 42 are also mountedin the casing 25,

the same being relatively smalland the gear 41 being fixed upon the rearend portion 'of the counter shaft 37 and meshing at all times with thesmall gear 42 which is mounted upon a sub-shaft or pin 43, mounted onthe rear Wall of the casing 25. The small gear 42 is adapted to mesh attimes with the shiftable gear 34 on the drive shaft section 35.

The automatic gear shifting mechanism of this invention is adapted to beapplied to this transmission mechanism, and the major portions of theautomatic mechanism may be housed within a casing 44, which is suitablymounted uponfthe top of the transmission casing 25. The top of thetransmission casing 25 is open in the usual manner, and in 'lieu of theordinary closure plates and mechanism carried thereby, the presentinvention provides a supporting plate 45 which is se cured by bolts 46or the like to the top of the transmission casing and over the openingtherein. The plate 45 1s provided with two longitudinal slots 47downwardly through whichproject f0rks48 and49 which engage the collars36 of the gears 33 and 34. The

forks 48 and 49 each have a hollow head 5O- latches that will behereinafter specifically pointed out.

The fork 48 is the intermediate and high speed fork, and the lug thereofis provided with a transverse pin upon which are pivotally mounted thehigh speed latch 56 and the intermediate speed latch 57, the latchesextending forwardly and rearwardly from the pin 55. The fork 49 controlsthe low speed and the reverse speed, and the lug- 54 thereof'carriesupon its pin 55 the low speed latch .58 and the reversing latch 59. Thelatches. are all disposed in parallel relation and are provided withdownwardly directed hooks 60, the shoulders of which face inwardlytoward one another. The inner ends 7 or heels of the forwardly extendinglatches are provided with depending arms 61 which havetheir lower endscurved latterly beneath the adjacent rear latches and which areconnected to the lower ends of springs-62. The

upper ends of the springs 62 are connected to the adjacent portionsofthe rear latches so that the springs 62 urge the latches downwardlytowards the plate 45. There is a spring 62 for each pair of the latchesof each head 50. I

The rear latches 57 and 59 are each provided with adownwardly offset andforwardly extending heel portion 63, and the heel portions 63 are notonly spaced apart transversely'of the device but also with respect tothe forward latches 56 and 58-. The springs 62 thus urge the heelportions 63 upwardly and the forward latches downwardly,

and for holding the latches in proper position and selectively operatingthe same, a selector cam, such as shown in Figures 7, 8, and 9, isemployed and is positioned between the forward latches 56 and 58 and theheels 63 of the rear latches. This selector cam is indicated generallyat 64 and is provided with peripheral grooves 65, one for each forwardlatch 56 and 58, and one for each heel 63 of the rear latches. Thebottom wall of each groove 65 is provided at one side with a depressedor cam portion 66 in the form of a Hat side adapted to permit themovement of the registry latch or heel portion inwardly towards the axisof the cam, and these cam portions 66 are angularly spaced about theselector cam 64 so that the latches may be lowered not only oneat atime, but by the rotation of the cam the desired latch may be lowered. a

- The selector cam 64 may be turned in any suitable manner, and by anysuitable mechanism. In the present instance, the cam 64 is mounted in apair of bracket: arms 67 which extend upwardly from the plate 45, andthe carnis provided with a shaft 68 mounted to turn in the brackets 67One end of the shaft 68 disclosed as connected to a flexible shaft 69which may be carried upwardly in the vehicle for easy access of theoperator, and which, as shown inFigure 1, may extend upwardly of thesteering column 7 0 and be provided upon its upper. end witha radiallyswinging arm 71 suitably shaped for grasping by the fingers to swing thearm 71 in opposite directions, and which is preferably upon itsfree endwith a pointer or indicator adapted to traverse an indicator 72. Theindicator 72 may be in the form of a sector plate secured about theupper end of the shaft 69 by means of a bracket 73 or the like securedto the steering column 70. The indicator 72 may be provided along itsmarginal portion with suitable indicia indicating the various positionsof the cam 64, Figure 2 showing the indicia as indicating reverse by theletter R, neutral by the letter N, low speed by the letter L,intermediate speed by the letter I, andhigh speed by the letter H.Spaced beneath the forward latches 56 and 58, and beneath the hooks 60thereof, is a forward shifting dog 72, and beneath the hooks 60 of therear latches 57 and 59 is disposed a rear shifting dog 73; 7 Eachshifting dog maybe made of one or more parts and, as shown in Figuresand 11, may be in the form of a single web which extends transverselybeneath the the dogs extend hpwardly and towards each a pinion 84 whichprojects into and interother at a slight angle. The shifting do 7 3 ismounted upon a collar or sleeve 74 lied to a shaft 75 pivotally mountedin ears 76 which extend upwardly from theplate 45.

Each of the shifting dogs, such as the dog 73 as shown in Figures lOand11, is provided with a depending neutral setting dog 77 which isrecessed at its lower edge portion and provided.with a, shiftablecontact piece 78 normally urged downwardly by a spring 79 for engagementwith the adjacent ends of the shifting rods 32. The'neutral setting dogs77 are of sufficient length to engage and slide the rods52 to neutralposition and to escape past the adjacent ends of the rods so as to leavethem in neutral position and admit of the continued swinging of theshifting dog 73. The shaft 75 is provided at one end with an arm 80 towhich is pivotally connected one end of a connecting rod 81 whichextends forwardly and has pivotal connection with a second arm 82mounted on a shaft 83 which may have bearing near its opposite ends inthe casing 44.

The shaft 83 is providednear one end with meshes with the internal teethof an actuating sector 85. It is noted that the arms 80 and 82 extend inopposite directions, the arm 80' extending downwardly and rearwardlywhile the arm'82 extends upwardly and rearwardly so that theconnectingrod 81 extends above and below the axes of the shafts 75 and 83. Thus,the shifting dogs 7 2 and 73' are moved toward and from each other, orin opposite directions. The actuating sector 85 is provided with a hubportion 86'mounted to turn upon the clutch pedal shaft 30, and may 'beheld from axial movement on the shaft in fixed sup ort. The block 88 andrecess 87- are ofsuc relative dimensions that the clutch pedal 31 isadapted to be'moved through sub stantially one-third of its operatingstroke before the block 88 engagesthe end of the recess 87 and transmitsthe motion of the shaft 30 to the actuating sector 85. The purpose ofthis lost motion is to insure suflicient movement of the clutch'pedal 31for releasing a the clutch member 23 before the shifting mechanism isset in motion. It will be noted,

particularly from Figure 1, that the shafts 75 and 83 are so positionedbeneath the hooks 60 of the latches that the shifting dogs 72 and 73must necessarily reach a subst-antiall Vertieal position coaxially withthe sha ts 75 and 83 before the shifting dogs engage the hooks 60.During the initial swinging movement of the shifting dogs 72' and 73,the

neutral setting dogs 77 are brought into engagement with the ends of theshifting rods 52 and move the same to iieutral position before theshifting dogs 72 and 73 are brought into P fly.

The operation of the improved automatic gear shifting mechanism is asfollows:

Assuming that the parts arein neutral position, such as shown in Figure1, when it is desired to change the speed transmission mechanism intohigh gear, such as shown in Figure 3, it is first necessary to swing theindicator arm 71 on the steering column'70 until the pointer of the armis brou ht'opposite to the indicia letter H. This adjustment of the arm71 turns theselector cam 64.

sufficiently to withdraw the clutch element 23,

and disconnect the power shaft 20 from the transmission mechanism. Assoon as the clutclris released, the block 88 engages the hub 86 andcarries the actuating sector 85 with the clutch, the sector 85 swingingfor forwardly against the tension of the spring 90 and with the clutchpedal 31. The actuating sector 85 now turns the pinion 84, ro tates theshafts 83 and 75 and swings the shifting dogs' 72" and 73 forwardly andbackwardly, respectively. During this move-- ment, the neutral settingdogs 77 strike the adjacentends of therods 52, if the latter are not inneutral position, so as to correctly position all of the parts. Theselector cam 64 holds all of the latches in'raised position with theexception of the one latch v56 which has been released on account of theregistration of the cam or depression 66 therewith. In this case, theforward shifting dog 7 2' is brought into'engagement with the shoulderof the latch 56 so as to couple the latch to the shifting dog and tothus couple the fork 18 to the mechanism. The continued movement of theclutch pedal 31 turns the shaft 83 and slides. .the fork 48 forwardlywith its gear 33 so as to interlock the gear 33 with the gear 32 on thedrive shaft 24. This position of the part is shown to advantage inFigure 3 wherein I the mechanism is in high gear and the clutch thespring position opposite the indicia letter which causes the selectorcam (34, to hold all pedal is about to be released so as to interlockthe transmission mechanism with the drive j of the latches in raisedposition out of the ming such as may paths ofthe dogs 72 and 73. Whenthe clutch 31 is now released, the shafts 83, and. '75 are so turned asto swing the shifting dogs 7 2 and 7 3', the latter being operatedmerely for the purpose of swinging the neutral set ting dogs 77 adjacentends of the shifting rods 52 and move them asshown in Figure 1. Theclutch maynow be released by the operator so that the transmission willnot be in gear. The rear shift ing dog 73 operates in a similar mannerthrough the connecting rod 81 so as to shift the gearing into theposition-shown in Figure .4 so that the transmission of the powerthrough the automobile isin a reversed direction. In this instance, thecam 64 is so turned as to release the latch 59 and permit it to dropinto the path of the dog 7 3' so thatas the latter moves rearwardly thefork 9 with its gear 34 is moved into intermeshing relation with thereversed gear 42.

The arm 71 is utilized for setting the mechanism to the selected gearratio while the mechanism is not actually operated or set until afterthe clutch has been released, and after each operation the mechanisminsures the neutral positioning of allof the parts of the apparatus andthe gearing so that there can be no interlocking of the parts or jambethe case when a hand control shifting lever is used. It is thus seenthat the mechanism is entirely automatic and'at the same; time ischecked in its opera tion by a predetermined releasing of the clutch.Thespring pressed plate 78 of the neutral setting dogs 77 are adaptedtoretract and snap past the ends of the guide rods so that all of sothat thelatter may engage the hack into neutral position, such ing said.member 52 after thel'atterhave been shifted into position beneath thedogs 77, and prior to the returning of the positions of rest. The not beretracted when t e dogs 77 are swung. upwardly from their positions ofrest so that the shifting-dogs 7 2" any partof the mechanism until allof-the mechanism is returned to a strictly neutral position, such asshown in Figure 1. g

, It is of course'understoodthat various changes and modifications maybe made in. -,-the details of construction and design of the abovespecifically described parts of this in- .vention without departing fromthe spirit thereof, such changes and modifications being restricted onlyby the scope of the following claims.

'What is claimed is;

1. In combinationwith the transmission gearing-and clutch of anautomobile, a plate dogs to their normal late 7 8, however, can.

and 73. can not operate I for attachment above the gearing mechanism,

a pair of slidable members mounted on the plate and having forks for.engaging the gears of the transmission mechanism, a pair of oppositelyextending latches carried by andabove each member, a shifting dog beyondeach .end of the slidable members arranged-for interlockingengagement with said latches, lost motion operating means for connectionwith the clutch to operate the 'shifting'dogs and move the same inopposite directions, and a selecting device connected to said latchesadapted to release the same one at a time for engagement with saidshifting dogs to slide said members in the selected direction.

2. In combination with transmission geaa ing and a clutch, a havingforks for engaging the shiftable gears of the gearing, a pair ofoppositely extending latches carried by said members, shining dogsarranged beneath said latches, a lost motion connection between saiddogs and the clutch for swinging the dogs upon the predeterminedmovement of the clutch, a selector member supporting said latches out ofthe path of said dogs, said selector member having releasing portionsthereon,jmeans for adj ustfor moving the releasing portion into registrywith theselected latch whereby said latch is adapted to moveinto thepath of the adjacent dog, and means for returning the-parts to normalposition to adjust the transmission gearing into neutral position,

3. Incombination with transmission gearing and a clutch therefor, a pairof independentlyslidable members connected to the sliding gears of thetransmission, a pair of oppositely extending latches mounted on eachmember, a shiftingxdog pivotally mounted beneath the freeends of saidlatches, means for holding theflatches in raised position out of thepath of said dogs, mear s for selectively pair ofslidable members aposition.

releasing the latches one at atime for position in the path of theadjacent dog, and a .lost motion clutch connection between the the dogssubsequent to the release of the clutch and. 1

dogs and the clutch for operating shifting the selected member in theselected '-4. In combination with a change speed elements of thegearing,

tending'in opposite direction from each of gearing, shiftabl'e membersconnected to the shifting a pair of latches ex said members, o'ierating, dogs pivotally mounted beneath said means betweenthe latches,dogs and the clutch for actuating the dogs, a selector cam supporting.said latches out of the path of said dogs and provided with depressedportions adapted latches one at a time for releasing the latches formovement into the path of the adjacent dog, and manual indicating meansconnected to said selector cam for turning the same to the desiredposition to release the. selected latch. r

'5. In combination with transmission gearing and a clutch, a plate forattachment to the-transmission gearing, a 'pair of members slidablymounted on the plate and having connection with the respective shiftableelements of the transmission gearing. a pair of latches pivotallvmounted on each member ande'xtending' in opposite directions there from,means for normally urging said latches downwardly,'a selector'caminterposed between the, latches forsupporting the same in raised dogsarranged between the free ends of the oppositely extending latches andnormally out of the path thereof, means for selectively and a clutchtherefor, a pair of latches, lost motion for registration with theposition, lnterconnected swingingreleasing the latches for movement intothe path of said members, and a lost motion #:clutch connection betweensaid members and the clutch.

ing and a clutch, slidable' rods disposed above the {rearing and havingconnection to shift the shiftahle gears of the transmission, a

pair of latches secured at intermediate porthe depressing movement ofthe latches into the path of said dogs.

7. In combination with transmission gearing and a clutch, slidable rodsdisposed above the gearing and having connect-ion to shift 6. Incombination with transmission gear-- the shiftable gears of thetransmission,' a pair of latches securedat intermediate pora tions ofeach rod to move with the rods but having a pivotal movementfwithrespect to the rods. a pivotal shifting dog located beyond each end ofthe rods for engaging and shifting the latches when depressed, meanscoupled to the clutch for conjointly operating the shifting dogsselecting means operatively engaging the latches to control thedepressing movement of the latches into the path of said dogs, andoperatively associated Y for engaging the oppositeends of the rods tomove same to neutral position.

a neutral setting dog In testimony whereof, Ihave aifixed my signature.

FRED o. SPAHN.

with each'shifting dog.

